As electronic devices have become more common, the number of small electronic components that require testing has increased dramatically. In response to this need, automated equipment capable of testing large quantities of electronic components at exceedingly high speeds has become commonplace. For example, there is equipment of this type capable of processing 50,000 electronic components per hour.
In the testing of electronic components, certain problems are commonly experienced and are often exacerbated by decreases in the size of the component to be tested. These problems have placed significant limits on the maximum component processing rate achievable by prior art testing devices.
One problem is with the testing apparatus' internal transport mechanism. Most high-volume testing machines move the components to be tested from a feed or loading station to a testing station and then to a sorting station. The transport mechanism must not only be capable of moving the components in a highly precise and controlled manner, but must also be durable, relatively low in cost and enable the testing apparatus to achieve electrical contact with a component's side- and/or end-located terminals. This combination of attributes, in an optimum form, is not found in the prior art.
A second problem is that many components feature closely-spaced side-located terminals that need to be contacted simultaneously. This requires the test probe to have closely spaced leads that are aligned with the component's sidelocated terminals. The probe's leads must be also be capable of rapid and accurate movement. Furthermore, the pressure applied by each lead to a terminal of a component being tested must be precisely controlled since the pressure must be sufficient to obtain good contact while not being of a magnitude that will cause scratching or other damage to the terminal or to the lead. The necessary accurate positioning and control of the probe's leads have been extremely difficult, if not impossible, to achieve in the prior art, and have severely limited the throughput in prior art devices.